Head and cone support for therapeutic mechanism



Aug. 29, 1961 Filed July 17, 1959 D. T. GREEN ETAL 2,998,526

HEAD AND CONE SUPPORT FOR THERAPEUTIC MECHANISM 2 Sheets-Sheet 1 1/ 27 [[9 3556 FIG 2 I I 34 25 2O I? 46 2, 61 45 t 18 i 40 3 39 3 I INVENTORS DONALD T. GREEN D EDWARD SL'AGLE A flD/u/D l7 W 9, 1961 D. T. GREEN ETAL ,5

HEAD AND CONE SUPPORT FOR THERAPEUTIC MECHANISM Filed July 17, 1959 2 Sheets-Sheet 2 INVENTORS DONALD T GREEN BY EDWARD SLAGLE KEV/MW WV W FIG. 4

2,998,526 HEAD AND CONE SUPPORT FOR THERAPEUTIC MECHANISM Donald T. Green, Shaker Heights, and Edward Slagle;

This invention pertains to mechanisms for emitting beams of ray energy,and more particularly to medical therapy beam emitting devices of the type which utilizes one of a set of interchangeable collimating cones.

Ray beam emitting devices which use a selected one of a set of collimating cones to obtain an appropriate beam size are now well known in the art. Normally, these devices are for medical use and of the class known as therapy devices. Usually, a device which utilizes interchangeable cones for collimation is a device in which a radioactive isotope is used as the ray energy source.

In these devices a head is provided which houses a quantity of ray energy emitting substance. A beam passage is provided through the wall of the head and a means is associated with the beam passage to permit the selective emission of a ray energy beam. A tubular cl-' limating cone is positioned at the outlet end of the beam passage. The cone includes a shaped second beam passage which forms an extension of the head beam passage.

The cone passage is shaped to collimate the beam into a desired cross sectional configuration and area. The cone achieves this collimation by absorbing substantially all of the ray energy other than that which is permitted to pass through the cone beam passage, and the beam passage is of a selected geometric contour'to obtain the desired beam shape and area.

Since the desired beam characteristics vary both from patient to patient and with the type of therapy being conducted, it is necessary to provide selection in the collimation. In the class of mechanisms of this invention the selection in collimation is obtained by providing a set of collimating cones each having a beam passage of a contour difierent from the other beam passages, and then selecting the appropriate cone for the patient and treatment under consideration.

In previously known mechanisms the interchange of cones has been a cumbersome and tedious task. The mechanisms provided for holding a cone while permitting the interchange of the cones have been unduly intricate and complicated. Since these mechanisms have been intricate and complicated, inherently they have also been unduly susceptible to mechanical failure.

With this invention a magnet means is provided to hold the cone in place. When so held, the cone may be rotated relative to the head to a desired position. In addition, a guiding and positioning mechanism is provided to permit a cone to be located and connected to the head quickly and accurately. A cam release mechanism is also provided to assure facile and ready removal of a cone from the head.

With prior mechanisms rather intricate bearing structures have been required. The device of the present invention has a simplified bearing arrangement in the form of flat complemental surfaces which are in sliding contact-there is very little load forcing the surfaces together. This is accomplished by permitting the cone to hang from the magnets such that the force bringing the two surfaces together is the difierence between the strength of the magnetic field and the weight of the object.

Accordingly, one of the principal objects of this invention is to provide a novel and improved simple and dependable cone support arrangement which permits ro- YT n dswss Pa ?1i1 f0 tation of the cone with very nominal frictional resistance. Another of the principal objects of the invention is to A further object of the invention is to provide a novel and improved cone supporting structure which permits facile connection and removal of a cone from a supporting head.

Still another object of the invention is to provide a novel and improved cone supporting arrangement which permits ready rotation of the cone relative to the head but which at the same time permits the cone to be posi-' tioned in an infinite number of positions, rotatively speak:

ing, and which eliminates the need for any complicated brake or lacking mechanism to hold a positioned cone.

Another object of the invention is to provide a novel and improved ray energy device in which a collirnating cone is supported by a magnet and in which guides are provided to align the cone in the desired position relative to the head.

A related and more specialized object of the invention is "to provide a magnet supported cone in which a novel and improved release mechanism is provided to permit the facile removal of the cone.

Other objects and a fuller understanding of the invention may be had by referring to the following description andclaims, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a therapy device incorporating the novel and improved cone support ar-I' rangement;

FIGURE 2 is a sectional view, on an enlarged scale, of a cone, a portion of the head, and the fulcrum and camming arrangement for positioning and removing the;

cone;

FIGURE 3 is a sectional view of the device, in the. scale of FIGURE 2, as seen from the plane indicated by the line 3-3 of FIGURE 2;

FIGURE 4 is a sectional view of the device, in the scale of FIGURE 2, as seen from the plane indicated by the line 4-4 of FIGURE 3;

FIGURE 5 is a fragmentary side elevational view of a portion of the head showing that section which sup ports the cam arrangement and on an enlarged scale with respect to FIGURES 1 through 4; and

FIGURE 6 is a view corresponding to the view of FIG ure 5, on the same scale, showing the cam mounted on the head.

Referring to the drawings and to FIGURE 1 in particular a pair of overhead supports 10 are shown. A large shielding head 11 is supported by the supports or tubes 10. The head 11 includes a space, indicated in dotted lines at 12, which houses a suitable quantity of radioactive material, such as the radioactive isotope of cesium. The head 11 includes the usual mechanism for shuttering the cesium so that it is fully shielded when the device is not in use.

The head 11 is supported on a pair of gimbals 13 (only one of which is shown) to permit rotation of the unit about the gimbals 13. Thus, the head 11 may be positioned vertically by extending or contracting the tubes Iii. To further facilitate positioning of the head the tubes 10 may have an overhead support which permits horizontal positioning. The appropriate angle of incidence between the emitted ray energy beam and the head 11 is provided by positioning the patient and by rotating the head 11 about the gimbals 13. Appropriate beam size and shape is obtained by selecting and positioning an appropriate one of a set of cones. One such cone is'designated at 15 in the drawings.

The head 11 includes a beam passage 16 which is in communication with the cesium isotope, or other ray energy source when the device is in operation. The cone has a collimating beam passage 17 which when the cone is positioned on the head, is in axial alignment with the head beam passage 16. As will be seen by examination of the drawings the cross sectional shape of the disclosed cone beam passage 17 is square. The cone beam passage flares outwardly. Such a passage will provide an energy beam which is square in cross section with an area which increases in cross section when measured at locations which increase in distance from the source of energy.

The cone has a pair of frusto-conical shaped guided surfaces 18, 19 and an intermediate step surface 20. The surfaces 18, 19, 20 together define a guided section of the cone 15.

The head passage 16 has walls which define frusto-conical shaped guide surfaces 22, 23 and an intermediate step surface 24. The cone surfaces 18, 19, 20 are adjacent and complemental to the head surfaces 22, 23, 24 respectively when the cone is positioned. It will be seen that the frusto-conical shaped guide and guided surfaces index the cone into a position in which the two beam passages are in appropriate axial alignment when the cone is connected to the head. The surfaces 18, 19 and the complemental surfaces are as shown axially offset or stepped. This step-like construction permits the cone to assume the tilted position shown in FIGURE 4 without the guide and guided surfaces coming into touching or binding engagement when it is either being connected to or removed from the head 11.

A split plastic support ring 25 is provided. The plastic support ring 25 carries a plurality of permanent magnets 26, which are embedded therein. In the preferred and dis closed arrangement the split plastic ring is suitably fixed to the head 11 and forms a part of it. A circular protective and decorative shield 27 may surround the magnet ring 25.

An annual keeper ring is fixed to and forms a part of the cone 15. The keeper ring 28 is formed of a magnetic material which is capable of being attracted to and held by the magnets 26. The keeper ring 28 has a flat annul-ar magnet contacting surface 30 which is disposed in a plane normal to the axis of the cone beam passage. The lower surface of the magnet ring 25 and the included magnets are preferably machined together to form a smooth corresponding keeper contacting surface 31. The keeper contacting surface 31 is in a plane normal to the axis of the head beam passage 16. Thus, when the cone is positioned the planes of the surfaces 30, 31 are coincident and normal to the axes of the passages.

All of the surfaces of the cone which abut or are adjacent to corresponding surfaces on the head are circular and disposed concentrically about the axes of the passages.

Since the cone is supported by the magnets 26, there are no obstructions to relative rotation of the cone 14 and the head 16. Further, since the majority of the force of the magnets will be vertical, they are quite adequate to support a heavy cone but still permit relatively easy rotation for two reasons. These reasons are: (1) because the force of rotation is across the magnetic fields; and (2) because the force urging the complemental surfaces into contact is the difference between the force of the magnetic field and the weight of the supported cone. There is sufficient magnetic force to hold the cone in a selected position against rotation after it has been rotated. At the same time, the force against rotation is not so great as to hinder facile rotation of the cone.

This vertical support of a weight by magnetic forces while permitting guided relative movement in a horizontal plane produces one of the outstanding features of the invention. This is true because friction is reduced to a nominal value which is utilized to retain the cone in a concept is reversed such that magnetic repulsion is utilized to support the weight, it will be seen that the weight may be held in spaced relationship with the source of magnetic force so that substantially frictionless movement may be obtained.

One of the outstanding advantages of the invention is achieved through the novel and simplified arrangement for positioning a cone in the head and for removing the cone from the head. A fulcrum support 33 is fixed to the head by any suitable means such as rivets 34, FIGURES 2 and 3. A cam 35 is rotatively supported on a pivot 36. The pivot 36 is fixed to the head 11 opposite the fulcrum support 33.

The cam 35 includes a through bore 37 which is in sliding association with the pivot 36 to permit both relative rotation and relative rectilinear movement. The pivot 36 includes a flange 38 which is positioned in a counterbored portion 39 of the bore 37. The counterborc 33 extends from an outer end 40 of the cam 35 inwardly to a counterbo-re base 41. A spring 42 is positioned between the counterbore base '41 and the pivot flange 38. For the sake of appearance, a cap 45 is provided to close the counterbore 3 9.

When the cam is in the closed position, shown in all the drawings other than FIGURES 4 and 5, inner end 46 of the cam is in abutment with the head 11. A handle 48 is fixed to the cam 35 for manipulation of the cam. The cam '35 may be moved outwardly along the pivot 36 against the action of the spring 42 until a locating pin 49 (FIGURES 3, 4, and 6) is out of a locating bore 50. In the preferred and disclosed arrangement, the locating pin 49 is connected to and forms a part of the cam 35, while the locating bore 50 is formed in the head 11.

A stop pin 51 is, in the preferred arrangement, fixed to the head. The stop pin 51 projects into a stop recess 52 formed in the cam 35. The stop recess 52 coacts with the stop pin 51 to locate the cam in both cone holding and the cone release positions. These positions are slightly less than 90 from one another to facilitate connection of a cone, as will subsequently be described in detail. These two cam positions represent the extremes of the rotative travel of the cam.

A cone locating and support projection 54 forms a part of the cam 35. The projection 54 extends radially outwardly from the body of the cam. The projection 54 has an inward extension 55. The extension 55 overlaps the keeper ring 28 when the cam is in the cone holding position with a cone in place. When the cone is in the position of FIGURE 2 the fulcrum projection 33 and the extension 55 serve as safety catches to prevent the cone from being accidentally knocked free from the head. lf the cone is knocked away from the magnets the safety catches 33, 55 will nonetheless prevent its separation from the head, and the magnets will return the cone to its position once the transient force which knocked the cone loose has passed.

A cam finger 58 extends radially outwardly from the remainder of the cam 35. The cam finger 58 selectively engages a cam surface on the cone 15. In the preferred and disclosed arrangement the magnet contacting surface 30 is also the cam surface.

To remove a cone from the head the handle 48 is grasped and the cam 35 is shifted outwardly along the pivot 36 against the action of the spring 42. When the locating pin 49 is out of the locating bore 50 the inward extension 54 on the projection 55 has been shifted radially outwardly past the keeper 28. The handle 48 may then be rotated downwardly. As the downward rotation of the handle 48 progresses, the cam finger 58 acts against the keeper 28 to shift the cone away from the pull of the magnets 26. As the shifting movement is occurring the fulcrum projection 33 serves as a pivot point for the shifting of the cone away from he head. When the cam 35 selected and adjusted position relative to the load. If the reaches the cone release position at one extreme of its roi. 5 tativ'e' trait-almanac pin 51 comes into abutment with'a portion of the side wall of the stop groove 52. With the cain'35 'in this release position the cone is in its release position. When in the release position the cone is sufficie'ntly'out of the fields of the magnets 26 to drop out of thehea'd into the.waiting hand of an operator.

When. the cam 35 is in the cone release position, the 'acion of the spring 42 will urge the cam inwardly to index the locating pin 49 into a shallow dish-like recess 60. The coaction of. the locating pin 49 and recess 60 serves to mitigatethe chance of accidental closing of the cam 35. As is seen iii-phantom in FIGURE 6, the cam finger 58 is not quite vertical when the cam is in the cone release position. This facilitates the connection of a selected cone. To connect a selected cone to the head 11 all the operator need, do is first position thelkeeper 28 against the fulcrum :33. He. then pivots" the cone upwardly until the guide section of. the cone 15 enters thepassage 16. As the upward movement of the cone continues the keeper 28 come'into contact with the cam finger 58. Continued upward pivotal movement of the cone will cause the cam 35'to rotate until the stop pin 51 strikes a stop portion of the wall of the stop groove 52 at which time the cam is,rotatively speaking, in the cone holding position; At timethe locating pin 49 will be in axial alignment withith'e locating bore 50, and the spring 42 will snap the caminv'vardly until the inner surface 46 of the cam again abuts the head 11. While the invention has been described with a great deal of detail, it is believed that it essentially comprises a ray. energy emitting device having a head with a beam aperture guide surfaces, a cone having a collimating .passageand guided surfaces coactable with the guide surfaces, and magnetic means to hold the cone in position while permitting relative selected movement of the head and-cone. I Although the, invention has been described in its preferred Tform witha certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous; changes in the details of construction and the combination "and arrangement of parts may be resorted towithout departing from the spirit and the scope of the inventionas hereinafter claimed. What is claimed is:

l. A my energy emitting device comprising, a head member having a space therein for housing a ray emitting source, the head member having a ray beam passage extending outwardly from the space, said head member havinga circular guide surface disposed peripherally about the-passage, a-cone member having a through passage aligned with the head passage and forming an extension thereof, the cone member having a circular complemental guided surface adjacent the guide surface and coactable therewith to maintain the alignment of the passages on relative rotation of the members, magnet means carried by one of the members, the other of the members having a magnet keeper portion formed of magnetic material, said portion including an annular magnet contacting surface in sliding abutment with the magnet means, and said magnet contacting surface being disposed transversely to the axis of relative rotation.

2. The device of claim 1 wherein the complemental surfaces are both frusto-conical.

3. The device of claim 1 wherein the magnet means comprises a. non-magnetic ring like member and a plurality of spaced permanent magnets imbedded therein.

4. The device of claim 1 wherein the head and cone are first and second members, a cam is pivotally carried by the first member, a cam surface is provided on the second member and a handle is operatively connected to the cam and wherein rotation of the cam by actuation of the handle will separate the keeper from the magnet means.

5. In a ray energy emitting device having a ray emitting source and a head member housing such source, the

, 3 head member having aray-er'riitting aperture the c'ombination of a guide surfaceformed on said head member and circumscribing said aperture, a cone member having a collimating passage in alignment with said aperture, the cone member having a complemental guided surface coactable with the guide surfaces, said cone member being rotatable relative to said head member, a magnet carried by one of the members, the other of the members having an annular magnet contacting portion in sliding contact with the magnet, said portion being formed of a magnetic material, said cone being held in position with the complemental surfaces adjacent one another by the coaction of the magnet and the magnetic, portion, and cam means operably connectable to the members and actuatable to separate the magnet from the magnet contacting portion and thereby permit facile separation of the cone and the head.

6. A ray energy emitting device comprising, a head having a first beam conducting passage, a tubular cone operably connectable to the head and having a second beam conducting passage, said beam passages being in axial alignment, said cone having a guide section projecting into said first passage, said guide section having at least one frusto-conical shaped guided surface coaxial with said passages, said head having a frusto-conical shaped guide surface adjacent and complemental to said guided surface, an annularkeeper fixed to and forming a part of said cone, said keeper being peripherally disposed about the remainder of the cone and having a magnet contacting surface, magnet means carried bythe head and having a keeper contacting surface, and said keeper contacting surface being in abutment with said magnet contacting surface in a plane which is substantially normal to the cone axis.

7. The device of claim 6 wherein the member cone and head are first and second members, a cam is pivotally carried by the first member, a cam surface is provided on the second member and a handle is operatively connected to the cam and wherein rotation of the cam by actuation of the handle will separatethe keeper from the magnet means.

8. The device of claim 6 wherein the guided section includes a plurality of frusto-conical axially oifset guided surfaces and wherein the head has one frusto-conical shaped guide surface complemental to each of said guided surfaces.

9. In a ray device having a cone member rotatably carried by a head member and magnetic means holding the members together the combination of one of the members being an element including pivot means, a cam element pivotally mounted on the pivot means, a locator carried by one of the elements and oepratively engageable with the other of the elements to locate the cam element in a closed position, the elements being first and second elements, stop means carried by the first element and operatively engageable with the second element to locate the cam element in a cone release position, a spring in operative engagement with the elements to urge the cam axially of the pivot and to urge the locator into engagement, said cam element being rotatable from the closed position to the cone release position, the other of said members including a cam surface coactable with the cam to shift the members relatively from closed positions to cone release positions, and the cam including a cone support position forming an operative positioning connection between the members when the cam is in the closed position.

10. In a ray device having a cone member rotatably carried by a head member and magnetic means holding the members together the combination of one of the members including pivot means, a cam pivotally mounted on the pivot means, locating means operatively engageable with the cam and the one member to locate a closed position, stop means operatively engageable with the cam and the one member to locate a cone release position; a spring in operative engagement with the cam and the one member to urge the cam axially of the pivot and to urge the locating means into engagement, said cam being rotatable from the closed position to the cone release position, the other of said members including a cam surface coactable with the cam to shift the members relatively from closed position to cone release positions, and the cam including a cone support portion forming an operative positioning connection between the members when the cam is in the closed position.

11. The device of claim wherein said one member is the head and wherein said other member is the cone.

12. In a ray energy emitting device having a head element for carriage of a ray energy beam source and a beam passage, a cone carried by the head element in relatively rotatable relationship and wherein the cone has a beam passage in axial alignment with the head beam passage, and wherein magnetic means folds the head element and cone together, the combination of a pivot element fixed to the head element and having an axis substantially normal to the axially aligned passage axes, a cam element having a through pivot bore, the bore having walls disposed in peripheral abuting relationship about said pivot, the cam element having an inner head contacting end abutable against the head and an outer end, the cam element having a counterbore coaxial with the pivot bore and extending from the outer end inwardly toward the head end, the counterbore terminating at a base, the pivot having an enlarged flange at its outer end, a spring interposed between the flange and the counterbore base and urging the cam element toward the head element, a locating pin cam'ed by one of the elements, a locating bore formed in the other of the elements for receipt of said pin, said pin being urged into said bore by said spring when the pin and the bore are in axial alignment, the elements being first and second elements, the first element having a guide stop recess formed therein, a stop pin carried by the second element and projecting into the stop recess to limit the relative rotation of the elements about the pivot, said locating pin being abutable against said other element when the pin and locating bore are out of axial alignment whereby to retain the spring in compression, a handle fixed to and forming a part of the cam element, the cam element being coactable with the cone to move the cone relative to the head element and against the action of the magnet means to a separated position, said cam element including a positioning projection coactable with the cone to urge the cone toward the head element and into a magnet means supported position, and a cone supporting fulcrum fixed to the head element opposite the cam element, the fulcrum serving as a pivot for the cone when it is shifted from the separated position to the supported position and from the supported position to the separated position.

13. In a ray energy emitting device having a head for carriage of a ray energy beam source and a beam assage, a cone carried by the head in relatively rotatable relationship and wherein the cone has a beam passage in axial alignment with the head beam passage, and wherein magnetic means holds the head and cone'tog'ether, the combination of a pivot fixed to the head and having an axis substantially normal to the axially aligned passage axis, a cam having a through pivot bore, the bore having walls disposed in peripheral abuting relationship about said pivot, the cam having an inner head contacting and abutable against the head and an outer end, the cam having a counterbore coaxial with the pivot bore extending from the outer end inwardly toward the head end, the counterbore terminating at a base, the pivot having an enlarged fiange at its outer end, a spring interposed between the flange and the counterbore base and urging the cam toward the head, a locating pin carried by the cam, a locating bore formed in the head for receipt of said pin, said pin being urged into said bore by said spring when the pin and the bore are in axial alignment, the cam having a guide stop recess formed therein, a stop pin carried by the head and projecting into the stop groove to limit the rotation of the cam relative to the head, said locating pin being abutable against said head when the pin and locating bore are out of axial alignment whereby to retain the spring in compression, a handle fixed to and forming a part of the cam, the cam being coactable with the cone to move the cone relative to the head and against the action of the magnet means to a separated position, said cam including a positioning projection coactable with the cone to urge the cone toward the head and into a magnet means supported position, and a cone supporting fulcrum fixed to the head opposite the cam, the fulcrum serving as a pivot for the cone when it is shifted from the separated position to the supported position and from the supported position to the separated position.

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